Statistics 1 Flashcards
Define discrete data
Data that can only take specific values e.g. shoe size, number of balls
Define continuous data
Data which can take any decimal value e.g. height, weight
Define quantitative data
Numerical values e.g. number of hours on homework
Define qualitative/ categorical data
Non numerical values e.g. colour of objects
Define what a census is
Select an entire population of items and get unbiased results
Define a population
The whole set of items which are of interest to
Define a sample
Some subset of the population is intended to represent the population
Define a sampling unit
Each individual item in the population that can be sampled
Define a sampling frame
A list of individually named or numbered sampling units of a population
Give an advantage of a census
Gives completely accurate results
Give a disadvantage of a census
- Time consuming and expensive
- Cannot be used when testing involves destruction
- Large volume of data to process
Give advantages of a sample
- Cheaper
- Faster
- Less data to process
Give disadvantages of a sample
- Data may not be accurate
- Data may not be large enough to represent small sub groups
Define random sampling as a whole
This is where we want each sampling unit in our sampling frame to have an equal chance of being chosen to remove bias.
Define simple random sampling
This is where every sampling unit in the sampling frame has an equal chance of being selected.
How is a simple random sample carried out?
In a sampling frame, each item is assigned a number from 1-Whole population number. Then use a random number generator to generate and selected an amount of unique numbers. Choose the items corresponding to the numbers.
